The present invention relates to a method for inserting windings into the grooves of stator coils and armatures in electric motors.
The invention further relates to an apparatus for carrying out such a method. The apparatus includes an insertion tool movable along the slots with the windings arranged on needles which are capable of insertion into the grooves.
Previously known methods and apparatus for inserting coils or windings into the grooves of stators or armatures of electric motors employed drawing needles which were disposed circularly on a die so that when a lifting movement of the insertion tool occurred, the windings located or carried by the needles were pressed into the corresponding stator or armature slots. The described method was complicated in that it was necessary to achieve a precise location of the needles and excessive frictional forces developed where there was a clamping relationship between the windings and the needles which frequently led to damaging of the windings and the draw-in needles and the protective lips thereof.
The problem was further complicated by the need for different length of coils, which necessitated individual adjustment of the needle length. As a consequence, there was time-consuming effort involved in the insertion process and frequent damage to both the coil and the needle resulted. Also, because of the "pressing in" of the coils there were high cross-forces which developed between the needle and the windings, tending to cause damage or breakage in extreme cases.